U.S. Pat. No. 7,718,395 discloses a method for the use of a transparent indicator reagent including a fluorescent substance as a method for determining whether cleaning has been sufficiently performed. This method includes a step of coating the indicator reagent on an object to be cleaned (e.g. table, chair, or the like) prior to cleaning, and a step of determining after cleaning whether or not the indicator reagent is present by sensing light emitted from the fluorescent substance due to irradiation, by ultraviolet radiation, of the object to be cleaned.